| arduousness(noun, trouble, difficulty, pain, struggle) |
| hardness(noun, difficulty, toughness) |
| complexity(noun, difficulty, adversity, complication, intricacy) |
| complication(noun, trouble, difficulty, pain, struggle) |
| difficulty(noun, difficulty, situation, problem, adversity) |
| might(noun, force, power, strength, ability) |
| toughness(noun, difficulty, hardness, tedium, arduousness) |
| assiduity |
| onerousness(noun, difficulty, exertion, laboriousness) |
| power(noun, control, strength, energy, ability) |
| strength(noun, control, force, power, ability) |
| activity(noun, exertion) |
| adversity(noun, trouble, difficulty, pain, struggle) |
| diligence |
| energy(noun, control, force, power, strength) |
| force(noun, control, power, strength, ability) |
| intricacy(noun, adversity, complication, complexity, complicatedness) |
| labor(noun, trouble, difficulty, pain, struggle) |
| laboriousness(noun, trouble, difficulty, pain, struggle) |
| potency(noun, force, power, strength, ability) |